Efficacy and safety of rigosertib in patients with recessive dystrophic epidermolysis bullosa-associated advanced/metastatic cutaneous squamous cell carcinoma

British Journal of Dermatology
Open Access

Clinical Summary

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What was studied

Two investigator-initiated, open-label, single-arm phase 2 studies in Europe and the US evaluated rigosertib (oral or intravenous) for anti-tumor activity and safety in five patients with RDEB-associated locally advanced and/or metastatic cutaneous SCC who had failed standard care, with 12 months of monitoring.

Key findings

Of five treated patients, two achieved complete responses within six months. Treatment showed anti-tumor activity with acceptable toxicity, quality of life was not negatively affected, and drug absorption exceeded prior populations.

Study limitations

Extremely small sample (n=5) and uncontrolled, open-label design without a comparator. Heterogeneous administration (oral vs IV), and pharmacokinetics were assessed in only four patients.

Clinical implications

Rigosertib produced signals of efficacy with tolerable safety in RDEB-associated advanced/metastatic cutaneous SCC after standard care failure, including two complete responses by six months. Given the tiny, uncontrolled dataset, this remains investigational and needs confirmation in larger controlled studies.